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factory5150
10-22-2013, 06:57 PM
Hey guys,

I have been having this annoying issue ever since I assembled my machine. It has been tolerable but now its to the point where it hardly moves without the motor stalling out. I am suspect that the gantry bearing blocks preload adjustment is to blame. I dont have the slightest clue how to adjust them to get them to stop stalling the motor. I tighten them (what seems) equally and it doesn't really get better. I adjusted them and ran the gantry back and fourth and it seemed all was well. Ghost ran a program and the motor stalled out. I took a quick video showing what is happening. Any tips or something that can get me out of this jam? Id love to upgrade the bearings to something that wouldnt give me so much trouble.

Please help!

X axis motor stalling - YouTube (http://www.youtube.com/watch?v=rweyVQswNZQ)

Thanks,
Chris

DiaLFonZo
10-23-2013, 06:34 AM
Ok, if you un power the motors.
Can you turn he ballscrew by hand?

I don't see the bearing ir anything in the video.

If they are linear rails, you don't need adjust on them, but the rail have to be aligned when you tight it to the frame.

From your video, it seems more of a controller setup problem.

What software and setting do you have?

factory5150
10-23-2013, 12:31 PM
Ok, if you un power the motors.
Can you turn he ballscrew by hand?

I don't see the bearing ir anything in the video.

If they are linear rails, you don't need adjust on them, but the rail have to be aligned when you tight it to the frame.

From your video, it seems more of a controller setup problem.

What software and setting do you have?

Yeah I can turn the ballscrew by hand. What it looks like to me is when the gantry is changing directions there is just enough play in the bearings that one side slightly moves before the other side. Which results in the gantry stalling out the motor. When I jog the long axis back and fourth I can grab one side of the gantry with my hand and produce the same result. Thats why I am thinking its a bearing problem rather than a software/controller problem. However I am open minded and am more than willing to try any suggestions.

They are not linear rails. They are round supported rails with an open end bearing block. There are 2 to each side. They look like this:
http://cdn.nexternal.com/kval/images/thospb320-abb.jpg

I am using mach3. I can post a config file if you like. I had a mach issue a while back and I posted my config file on the mach support site and they said everything looked good (except my issue which was resolved.) The machine was running like a swiss watch. I have not used the machine in a month and last weekend when I was doing a run the long axis motor was randomly stalling. I have a gecko g540 and the stepper motor cables are shielded.

If you need any other info, ill be more than happy to provide.

Note this is one of George's early machines. Everything on his end is good to go. I have a feeling my issues are an assembly/user error, not poor worksmanship.

Chris

DiaLFonZo
10-23-2013, 12:34 PM
Could be the motor setup in mach3...

Envoyé de mon HTC One en utilisant Tapatalk

gio666
10-23-2013, 11:23 PM
Hi Chris, seems like the acceleration setting in mach3?
The bearing when to tight will pull on one side if one is to tight. The bearings just tighten enough so the gantry don't rack or move on rails. Supported blocks are very tricking to adjust right . But dont see bearings causing problem from stop to opposite direction. Always has been in setting when that has happened or power supply not keeping up

factory5150
10-24-2013, 08:22 AM
I have the rapid set to 150ipm and the acceleration to 5ipm on the long axis. Is there something else I should tweak like motor pulse or anything else other than the motor tuning it self? Im pretty sure I got the power supply from you George so it should be able to handle the load?

Any trick to tightening up the blocks so even tension is applied? My logic is to tighten them so you cant grab the gantry with the motor off and pull one to the side but I could be wrong?

Would a smooth stepper help any?

Looks like my issue is both hardware and software related. I keep tightening/loosening the bearings thinking that will solve my problem but I guess I am just making it worse lol.

inventor83
10-28-2013, 04:43 PM
You might be having resonance issues. I have the same machine(supported rails) and I was having all kinds of problems with axis stalling. I got rid of it by using 1/4 microstepping. Another thing to note : Pull the bearings off and apply some bearing grease inside the C bearing rather than applying it directly to the shaft.

Matt

jassaf
11-10-2013, 12:17 PM
I have the rapid set to 150ipm and the acceleration to 5ipm on the long axis. Is there something else I should tweak like motor pulse or anything else other than the motor tuning it self? Im pretty sure I got the power supply from you George so it should be able to handle the load?

Any trick to tightening up the blocks so even tension is applied? My logic is to tighten them so you cant grab the gantry with the motor off and pull one to the side but I could be wrong?

Would a smooth stepper help any?

Looks like my issue is both hardware and software related. I keep tightening/loosening the bearings thinking that will solve my problem but I guess I am just making it worse lol.

The machine does not have good movement.
The following is the sound of a excelent movement of the "X" axis:


http://www.youtube.com/watch?v=dXWvqUabZqw

or

CNC Mach3 USB AKZ250 Test @ - YouTube (http://www.youtube.com/watch?v=Y9oSxQU2pvE)

you tested to stop the Gantry with your hand when you are moving?
if you can Stop it (or the noise appears), will be confirmed the acceleration problem.

You must modify the setup of the "motor tuning"... I think that 5 IPM is little.
You should also consider lowering the velocity: you should start with 100ipm and increase gradually.

gio666
11-26-2013, 07:23 PM
Hey guys,

I have been having this annoying issue ever since I assembled my machine. It has been tolerable but now its to the point where it hardly moves without the motor stalling out. I am suspect that the gantry bearing blocks preload adjustment is to blame. I dont have the slightest clue how to adjust them to get them to stop stalling the motor. I tighten them (what seems) equally and it doesn't really get better. I adjusted them and ran the gantry back and fourth and it seemed all was well. Ghost ran a program and the motor stalled out. I took a quick video showing what is happening. Any tips or something that can get me out of this jam? Id love to upgrade the bearings to something that wouldnt give me so much trouble.

Please help!

X axis motor stalling - YouTube (http://www.youtube.com/watch?v=rweyVQswNZQ)

Thanks,
Chris

Having a 2005 ballscrew i think you have ,it would take a lot more amps when changing direction because higher torque you have with low pitch of screw. Having a switching power supply, you don't know what load on that power supply, i seen some switching 48v power supply's drop to 30v from just moving. An open frame power supplys are the best to use